1. Field of the Invention
Exemplary embodiments of the present invention relate to a photoresist composition, a method of forming a pattern using the photoresist composition, and a method of manufacturing a display substrate. Particularly, exemplary embodiments of the present invention relate to a photoresist composition for a digital exposure device, a method of forming a pattern using the photoresist composition, and a method of manufacturing a display substrate.
2. Discussion of the Background
Generally, a display substrate including a thin-film transistor (“TFT”) is formed by a photolithography process. The photolithography process includes an exposure step, a developing step and an etching step. In the exposure step, a photoresist pattern is formed using a mask reflecting a design of a pattern and an exposure device (hereinafter, general exposure device). A lower layer of the photoresist pattern is patterned using the photoresist pattern as an etch stopping layer to form the pattern. Whenever the design of the metal pattern is changed, the design of the mask needs to be changed so that the number of the masks depends on the number of the metal patterns. Due to the high cost of manufacturing the mask, increasing the number of masks used for the photolithography process increases the manufacturing cost for the display substrate. Recently, in order to solve the above-mentioned problem, a digital exposure device has been used. The digital exposure device uses an optical element including a plurality of micro-mirrors capable of providing a plurality of spot beams onto a substrate without using an additional mask.
However, the digital exposure device uses a light source generating a light having a wavelength different from the general exposure device. Thus, when a photoresist composition appropriate for the general exposure device is used for the digital exposure device in the photolithography process, photosensitivity may be decreased so that the residue rate may be increased and the linearity of a photo pattern formed using the photoresist composition may be decreased. In addition, since the digital exposure device uses the spot beams, an exposure region may not receive a uniform light from the digital exposure device. Thus, the reliability of the photo pattern and a pattern formed using the photo pattern may be reduced.